Method for sanitizing shells of eggs using electrolyzed oxidizing water

ABSTRACT

The present invention relates to methods of sanitizing the shells of eggs, which are used for human consumption and also as hatchlings. More specifically, the present invention relates to a method of sanitizing eggs using an electrostatic sprayer with electrolyzed oxidizing water produced from an electrolyte solution. It is the overall objective of the present invention to provide a method for sanitizing eggs comprising the steps of passing an electrolyte solution through a water electrolysis machine in combination with feed water to produce electrolyzed oxidizing water, and then spraying the eggs with the electrolyzed oxidizing water by using an electrostatic sprayer which creates a negative charge on the spray droplets as they leave the sprayer.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of Provisional PatentApplication, Ser. No. 60/277,849 filed Mar. 22, 2002.

THE FIELD OF THE INVENTION

[0002] The present invention relates to methods of sanitizing the shellsof eggs which are used for human consumption and also as hatchling eggs.More specifically, the present invention relates to a method ofsanitizing eggs with electrolyzed oxidizing water (herein EO water)produced from an electrolyte solution and then spraying the eggs withthe electrolyzed oxidizing water by using an electrostatic sprayer.

BACKGROUND OF INVENTION

[0003] Egg products are an important part of the diet of the Americanpeople and of nations all over the world. Eggs are generally a very safefood source and are relied on by many as a good source of protein. Dueto their nutrient-dense character, eggs are also a good growth mediumfor bacteria. The United States weekly chicken broiler production ismore than 150 million per week and the consumption of chicken is rising.Eggs have been found which contain the bacterium Salmonella enteritidisin about one in every 20,000 eggs. Other bacteria of concern to thepoultry industry in the processing and sanitizing of eggs areStaphylcoccus aureus, Listeria monocytogenes and Escherichia coli.

[0004] A. WASHING AND SANITIZING EGGS USED FOR HUMAN CONSUMPTION

[0005] In order to assure that eggs remain a safe and dependable food,governmental regulations have been adopted which require the washing andsanitizing of eggs used for human consumption. Eggs are generally washedas quickly as possible after laying in order to remove soil and bacteriafrom their surface and to help prevent bacterial penetration of theshell. Today most eggs are cleaned in mechanical egg washers that employsprayers, brushes, detergents, rinses and dryers. Governmentalregulations require that the eggs not be immersed at any time, althoughthey may be sprayed with water at a temperature about the same as thetemperature of the wash water. After eggs are washed they are sprayedwith a sanitizing agent.

[0006] The present systems and methods of sanitizing eggs used for humanconsumption have many disadvantages:

[0007] (a). Presently used sanitizing agents are chemicals such asquaternary ammonium, phenolics and hydrogen peroxide. When thesesanitizing agents are used workers are required to wear protectiveclothing.

[0008] (b). The disposal of presently used chemical sanitizing agentsmay require special and expensive disposal methods in order to complywith environmental regulations.

[0009] (c). Because governmental regulations prohibit eggs from beingimmersed in wash water or a sanitizing agent, these are applied bysprayers. Many current sprayer technologies are limited in theireffectiveness because the sprayers only coat the surface of the eggwhich is directly in front of the sprayer. These methods attempt toobtain adequate coverage of the egg surface by rotation of the egg or byadditional different directional sprayers.

[0010] (d). With the present spraying methods the contact time of thesanitizing agent and the egg is limited to the flow time of the sprayoff the surface of the egg. The length of contact time of the sanitizingagent on the surface of the egg is a critical factor in theeffectiveness of the sanitizing agent.

[0011] OBJECTS AND ADVANTAGES

[0012] Several objects and advantages of the present invention are:

[0013] (a). Provides a sanitizing agent the use of which does notrequire special protective clothing.

[0014] (b). Provides a sanitizing agent that is environmentally friendlyand is free from toxins and harmful chemical residues and that can bedisposed of without any special disposal methods. Electrolyzed oxidizingwater can be disposed of by pouring it down the ordinary water sewer.

[0015] (c). Provides a system where the spray of the sanitizing agentfrom the electrostatic sprayer covers the entire surface of the egg andthe volume of the spray that adheres to the surface of the egg issubstantially increased.

[0016] (d). Provides that the spray of the sanitizing agent adheres tothe surface of the egg for a significantly longer time than presentsanitizing methods there by increasing the effectiveness of thesanitizing agent.

[0017] (e) Because of the electrical bond between the electrostaticspray droplets which have a negative charge and the surface of eggswhich have a positive charge less total sanitizing agent is requiredthan present spraying methods.

[0018] B. SANITIZING HATCHLING EGGS

[0019] Shell surface contamination of hatchling eggs is inevitable inthe breeder house. Hatchling eggs are usually set from one to ten daysafter they are laid. During hatching egg storage there is a greatmultiplication of the bacteria on the shell surface. This increases theprobability of bacteria invading the interior of the egg and destroyingthe developing embryo.

[0020] The present systems and method of sanitizing hatchling eggs havemany disadvantages:

[0021] (a) All of the disadvantages listed under the above section onthe present methods and systems of sanitizing eggs for human consumptionapply to the sanitizing of hatchling eggs.

[0022] Additional disadvantages of present systems and methods asrelates to hatchling eggs are as follows:

[0023] (b) A present alternative method to spraying hatchling eggs is tofumigate the eggs with formaldehyde gas. Formaldehyde gas burns peopleslungs and eyes when they are exposed to it. This requires the workers towear protective masks and clothing. Egg shells are porous and thedeveloping chick embryo needs a sufficient supply of oxygen. Too muchformaldehyde gas can kill some of the chick embryos.

[0024] (c) The present use of sprayed sanitizing agents such asquaternary ammonium, phenolics and hydrogen peroxide and fumigating withformaldehyde gas leaves toxic chemical residues on the egg shell whichcan clog its pores and deprive the developing embryo of sufficientoxygen.

[0025] OBJECTS AND ADVANTAGES

[0026] (a) All of the advantages of the present invention as relates tothe sanitizing eggs for the use of human consumption apply to thesanitizing of hatchling eggs.

[0027] Additional advantages of the present invention as relates to thesanitizing of hatchling eggs are as follows:

[0028] (b) Unlike formaldehyde gas, excess spray of electrolyzedoxidizing water on the hatchling eggs is not harmful to the developingchick embryo.

[0029] (c) The spray of electrolyzed oxidizing water on the hatchlingeggs leaves no chemical residue which would clog the pores of thehatchling egg.

BRIEF SUMMARY OF THE INVENTION

[0030] The objective of the present invention is to provide a method forsanitizing the shells of eggs comprising the steps of producing anelectrolyte solution, passing the electrolyte solution through a waterelectrolysis machine in combination with feed water, to produceelectrolyzed oxidizing water and then spraying the eggs with theelectrolyzed oxidizing water by using an electrostatic sprayer.

DETAILED DESCRIPTION OF THE INVENTION

[0031] The following more detailed description of the embodiments of themethod of the present invention is not intended to limit the scope ofthe invention as claimed but is merely representative of presentlypreferred embodiments of the invention.

[0032] Electrolyzed oxidizing water is a product which comprises anacidic solution having a pH of at least about 2.4-2.5 and below, and hasan oxidation-reduction potential of at least about 1100-1400 millivolts(“mV”). Electrolyzed oxidizing water has free chlorine in proportions ofabout 10 mg/L and hypochlorous acid in proportions of about 11 mg/L.

[0033] The present invention relates to the method of sanitizing eggswith electrolyzed oxidizing water produced from an electrolyte solution,and then sprayed on the eggs utilizing an electrostatic sprayer.Electrostatic sprayers break down the droplet size to about 30 micronsin diameter, and add either a positive or negative charge to the surfaceof each droplet. Because the surface of eggs have a positive charge andthe spray droplets have a negative charge the droplets are attracted tothe surface of the egg and surround the egg in an “electrostatic wraparound”. The electrical charge of the spray substantially increases thevolume of spray that adheres to the egg and substantially increases thetime that the spray stays on the egg thereby increasing its sanitizingeffect. Examples of these electrostatic sprayers are those built byElectrostatic Spraying Systems, Inc. Details available atwww.maxcharge.com.

[0034] In one presently preferred embodiment, an electrolyte solution ismade by combining tap or other water with a concentration of about 1% or50% sodium chloride. However, a concentration of 10% to 30% sodiumchloride is more preferable. In certain embodiments a concentration ofabout 20% of sodium chloride is preferred. In other embodiments the NaClmay be used in concentration of about 125 g/liter.

[0035] The sodium chloride in the electrolyte solution serves as themajor electrolyte in increasing electrical conductivity for the processof electrolysis. During electrolysis several ionic and non-ionicchemical species are generated including H⁺, CIO, H₂O₂. CI, HCIO, Cl₂and OH′. The combination of these ions, as well as the low pH and thehigh oxidation reduction potential (ORP) account for the bactericidalaction of the electrolyzed oxidizing water.

[0036] According to another embodiment of the invention, an electrolytesolution for producing electrolyzed oxidizing water includes sodiumchloride (NaCl) and sodium phosphate (NaH₂PO₄). Sodium phosphate addedto the electrolyte mixture provides a source of phosphate ions toincrease the cleansing action of the electrolyzed oxidizing water. Insome embodiments, the weight ratio of NaH₂PO₄ to NaCl can be in a rangeof from about 0.018 to about 0.040. In some embodiments, the NaH₂PO₄ canbe in a concentration range of from about 2.3 to 5.0 g/liter, and theNaCl in a concentration of about 125 g/liter.

[0037] The electrolyte solution contains sodium chloride (NaCl) andsodium phosphate NaH₂PO₄ which are dissolved in high quality tap water,deionized tap water, or softened (reduced calcium content) water.Suitable concentrations of these compounds for use in flow throughelectrolyzers are: NaCl 125 g/L NaH₂PO₄ 2.3-5.0 g/L

[0038] This is equivalent to a weight ratio of NaH₂PO₄ to NaCl of about0.018-0.040.

[0039] While the electrolyte may consist essentially of NaCl or NaCl andNaH₂PO₄, according to another aspect of the invention, the electrolytemay further include amidosulfonic acid (H₃NO₃S). In some embodiments,the weight ratio of H₃NO₃S to NaCl can be from about 0.005 to about0.008. In some embodiments, the H₃NO₃S to NaCl can be in a concentrationof from about 0.6 to about 1.1 g/liter. In these embodiments, theelectrolyte may consist essentially of NaCl, NaH₂PO₄, and H₃NO₃S. Whenamidosulfonic acid (H₂NO₃S) is added to make an electrolyte solution thefollowing concentrations are also suitable for use: NaCl 125 g/L NaH₂PO₄2.3-5.0 g/L H₃NO₃S 0.6-1.1 g/L

[0040] Here, in this example of an electrolyte solution, theamidosulfonic acid aids in preventing the accumulation of scale in theelectrolysis machine and may also add to the cleaning (solvent) actionof the product water from the electrolysis machine.

[0041] The above electrolyte solution with amidosulfonic acid was testedin a water electrolysis machine in combination with feed water that hadbeen passed through a bed of activated charcoal ion exchange resins, andfinally through 0.5 and 0.2 micron filters. Again, the electrolytesolution was passed into the machine at a volume ratio of 1:316 to feedwater that was passed through the machine. The electrolyzed oxidizingwater that was produced had an oxidative/reduction potential (ORP) of1,100-1,140⁺ mV and a pH of 2.7-2.3 The co-produced alkaline water had apH of 11.2-11.4 and an ORP of about 840-847⁻ mV. The combination of theprepared feed water and use of this electrolyte mixture is apparentlywell suited for use in flow through electrolysis machines. Over 5,000gallons of electrolyzed water were produced without change in the ORP ofthe water. This would indicate that the machine remained relatively freeof scale.

[0042] Pure water cannot be electrolyzed to any useful degree. Whenwater containing sodium and chloride ions (Na⁺, Cl) derived from thedissolution of NaCl when electrolyzed, the ions migrate to oppositeelectrical poles. Specifically, when electrical energy is supplied tothe electrolysis machine, Na⁺ flows in a net mass manner toward thecathode (−) and Cl⁺ to the anode (+).

[0043] Water is decomposed (electrolyzed) due to the high reactivity ofNa⁺:

Na⁺+2H₂O=2NaOH+H₂.

[0044] Since sodium ions are attracted to the cathode, the abovereaction occurs in the cathodic channel to form a small amount ofhydroxide as water flows through the channel. The sodium hydroxide(NaOH) ionizes as NaOH=Na⁺+OH′. The water from the cathode channel iscalled electrolyzed alkaline water. Electrolyzed alkaline water is anexcellent cleaning solution particularly with lipid-based or organicstains.

[0045] In the anodic channel, where chloride ions (CI′) accumulate,electrons from CI′ are given up to the electron deficient anode andhence:

2CI′−2e′=Cl₂

[0046] The chlorine is soluble in water and reacts with water as:

Cl₂+H₂O−HOCI+H⁺+CI′

[0047] This forms a small amount of hydrochloric and hypochlorous acidsas water flows through the channel. Typically hypochlorous acid ispresent at about 11 mg/L in the electrolyzed oxidizing water. Otherreactions occurring in the anodic channel include the formation of smallamounts of hydrogen peroxide and ozone (H₂O₂ and O₃). The water from theanode channel is called electrolyzed oxidizing water or acid water.Owing to these chemical species, the solution is both acidic andoxidative. The overall relative oxidative reduction potential (ORP) isin the range of 1100 to 1400 millivolts. Bacteria and viruses arereadily killed by this solution, but it is safe for humans and animals,even when it is accidentally ingested.

[0048] From the above it is clear that water molecules are split in bothchannels. When this chemistry is divided by a conductive diaphragm ormembrane, the net balance of chemical species is such that alkalinewater (pH 11.2 to 11.5) is derived from the cathodic channel, and acidoxidative water (pH 2.7 to 2.3) is derived from the anodic channel. Thisoverall process is driven by the input of electrical energy and hencedescribed by the term electrolysis.

[0049] While the above described examples recite the use of filteredwater as feed water, other types of water can be used for feed water,including tap water, deionized water, and distilled water, or acombination of any of the aforesaid feed waters.

[0050] The flow through electrolyzing system used in testing theelectrolyte mixture simultaneously produces both electrolyzed oxidizingwater and electrolyzed alkaline water. It is thought by someinvestigators that electrolyzed water is restructured such that thecluster size (number of water molecules that are weak-hydrogen-bonded toform molecular aggregates) is smaller than for ordinary water. Smallercluster size would predictably, reduce viscosity.

[0051] Electrolyzed oxidizing water produced as described above wastested for antibacterial effect. Between 10⁵-10⁶ bacteria isolated frompackaged chicken were added to one ml of acid water. After a 15, 30, 60and 120 seconds 25 μl aliquots were spread onto bacteriological agarculture plates. After 36 hours of incubation at 37° C., the plates werevisually examined for the presence of bacterial colonies. No colonies onthe plates were observed. In contrast, when sterile tap or distilledwater was used instead of the electrolyzed oxidizing water inidentically structured tests, the culture plates were covered withbacterial colonies visible to the naked eye.

[0052] Electrolyzed oxidizing water is effective in reducing the risk offood contamination by killing disease causing bacteria. The bactericidaleffect of electrolyzed oxidizing water obtained by electrolysis of tapwater was determined to be highly effective in killing bacteria Whenelectrolyzed oxidizing water is sprayed on eggs using an electrostaticspray device, a five-log reduction in bacteria is achieved.

[0053] Electrolyzed oxidizing water is an acidic solution having pH 2.6or below, oxidation-reduction potential (ORP) 1,100 mV or move, freehypochlorous acid of about 11 mg/L and free chlorine in the range ofabout 10 mg/L. An analysis of electrolyzed oxidizing water is shown onthe following Table: Replication 1 2 3 PH 2.39 2.41 2.41 ORP (mV) 11701166 1168 Chlorine (total, mg/L) 11 11 12 Chlorine (free, mg/L) 10 9 10HOCl (free, mg/L) 11 11 11 OCl (free, mg/L 0.3 0.3 0.3 Chloride ion(mg/L) 408 371 391 Sodium ion (mg/L) 161 159 163

[0054] The foregoing analysis was performed by Yen-Con Hung, Ph.D.,Professor of Food Science and Technology, University of Georgia,Griffin, Ga.

[0055] The use of electrostatic sprayers in the invention yieldsexcellent results by breaking down the size of the spray droplets thatare carried to the egg on an air stream. Such sprayers give anelectrostatic charge to the surface of droplets, as they becomeairborne. The electrical charge on the surface of the spray dropletscause them to be attracted to the egg. Also, the electrical chargeenables the spray droplets to alter their trajectories around the eggbeing sprayed, even to the point of entirely reversing their flightpath, in order to coat the back of the egg being sprayed. This action isoften referred to as “electrostatic wrapping”, and is dependent on theelectrostatic forces of the droplets dominating over gravity, inertia,and the force of air currents. Factors such as the size and weight ofthe droplets are also critical. The electrical charge of the spraydroplets substantially increases the volume of spray that adheres to theegg and substantially increases the time the spray stays on the surfaceof the egg thereby increasing its sanitizing effect.

[0056] The present invention may be embodied in other specific formswithout departing from its structures methods, or other essentialcharacteristics as broadly described and claimed herein. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive.

We claim:
 1. A method of sanitizing shells of eggs, both those used forhuman consumption and also hatchling eggs, by using electrolyzedoxidizing water comprising: a. Producing electrolyzed oxidizing water byusing an electrolyte solution containing sodium chloride (NaCl), and b.Spraying the electrolyzed oxidizing water on the eggs by using anelectrostatic sprayer that creates on the spray droplets a positive ornegative electrical charge.
 2. A method of sanitizing shells ofeggs,both those used for human consumption and also hatchling eggs by usingelectrolyzed oxidizing water comprising: a. Producing electrolyzedoxidizing waterby using an electrolyte solution that contains sodiumchloride (NaCl) and sodium phosphate (NaH₂PO₄), and b. Spraying thiselectrolyzed oxidizing water on the eggs by using an electrostaticsprayer that creates on the spray droplets a positive or negativeelectrical charge.
 3. A method of sanitizing shells ofeggs, both thoseused for human consumption and also hatchling eggs by using electrolyzedoxidizing water comprising: a. Producing electrolyzed oxidizing waterbyusing an electrolyte solution that contains sodium chloride (NaCl),sodium phosphate (NaH₂PO₄), and amidosulfonic acid (H₂NO₃S), and b.Spraying this electrolyzed oxidizing water on the eggs by using anelectrostatic sprayer that creates on the spray droplets a positive ornegative electrical charge.